This invention relates to a support assembly for supporting a control device relative to a fixed support or location such as a wall, platform or bench.
This invention in one preferred aspect is especially suitable for supporting a keyboard or other finger-operated device relative to a workbench or table which may support visual display apparatus such as the visual display unit (V.D.U) of a computer, word processor or other electronic equipment.
Hitherto it has been highly desirable to design apparatus for supporting a keyboard relative to a VDU whereby the keyboard was height adjustable relative to the VDU for the main reason that the position of keyboard operator was one that could be filled by a number of people of different heights who therefore would require varying keyboard heights for individual comfort and also to achieve maximum working efficiency. Such support apparatus would be considered preferable for example to apparatus that could only support the keyboard at a fixed height relative to the VDU such as a rigid support bracket interconnecting the keyboard carrier to a table carrying the VDU.
In one conventional apparatus of the type described above there was provided a keyboard support which was mounted on a tubular support shaft wherein a rod or tube attached to the keyboard support was telescopically engageable with the tubular support shaft and there was provided jacking means to make the keyboard support height adjustable relative to the support shaft. Located adjacent the keyboard support was the work platform or table. While this arrangement was satisfactory in some respects it was found that it was bulky or cumbersome and was difficult to operate by inexperienced personnel such as junior typists. Also the actuating mechanism for initiating movement of the keyboard support was often inaccessible.
In another conventional arrangement there was provided a keyboard support which was connected by a linkage arm to a fixed table which carried a VDU. The linkage arm operated on a pantograph or parallelogram linkage which was controlled by springs. When it was desired to lock the keyboard support in a desired position relative to the VDU it was necessary to actuate a mechanical locking arrangement which again was not always the most appropriate arrangement to be operated by inexperienced personnel. Also because of the spring control means often the movement of the keyboard support relative to the VDU was uncontrolled or jerky and did not give a smooth controlled movement. Also the mechanical locking arrangement was also found to be relatively difficult to operate in the case of inexperienced personnel and often the locking arrangement was relatively inaccessible to the operator.